It started with a low idle about 2 weeks ago, then about a week ago it kicked up to normal. Then it started climbing to 1500, then 2000 one day. Now it's fluctuating between 1400 and 2100, and floats up and down at about one cycle per second.
At first I thought it would be the idle speed motor, but unplugging it had no effect. I checked the voltage on the throttle position sensor and saw it a bit high, so I adjusted the TPS. It fixed it for about a day, then it started again.
I can get it to idle normal for a single drive cycle if I unplug the TPS before starting it. However, if I start it with the TPS connected, it won't idle right. I thought it might be a bad TPS, but testing it both on and off the car yields normal electrical readings.
Anyone have any ideas?
At first I thought it would be the idle speed motor, but unplugging it had no effect. I checked the voltage on the throttle position sensor and saw it a bit high, so I adjusted the TPS. It fixed it for about a day, then it started again.
I can get it to idle normal for a single drive cycle if I unplug the TPS before starting it. However, if I start it with the TPS connected, it won't idle right. I thought it might be a bad TPS, but testing it both on and off the car yields normal electrical readings.
Anyone have any ideas?